The present disclosure is related to equipment used in subterranean wells and, more particularly, to latch coupling assemblies and methods to position, anchor, and orient downhole tools.
In the oil and gas industry, it is often desirable to position a downhole tool or other piece of equipment at a known location within a well. For example, a whipstock is often positioned at a predetermined location within a well lined with a casing string to permit a lateral wellbore to be formed by cutting a window in the casing string and drilling the lateral wellbore through the window. A perforating gun may also be positioned at a predetermined location within a well lined with a casing string and operated to perforate the casing string at the predetermined location.
One method of positioning a downhole tool within a well is to provide an internal shoulder (e.g., a “no-go” shoulder) in the casing string at a predetermined location. A downhole tool or associated tubing string subsequently lowered into the casing string may include an external no-go shoulder able to locate and engage the internal no-go shoulder and thereby positively position the downhole tool at the predetermined location. This method, however, is not satisfactory in some situations. For instance, where operations are performed from a semi-submersible or floating rig, it may be difficult to maintain engagement of the no-go shoulders due to the tubing string rising and falling with ocean heave acting on the floating rig. Moreover, no-go shoulders are unable to provide angular orientation within a wellbore.
Another method of positioning a downhole tool within a well is to set a packer at a desired location within the well. The packer also seals against the casing string, which may be used to provide pressure isolation for the wellbore or may aid in preventing debris from falling further downhole within the wellbore. Various types of packers have been used for this purpose—permanent packers, retrievable packers, hydraulically set packers, mechanically set packers, etc. Nevertheless, each of these packers shares various disadvantages, such as encompassing complex configurations and components that are left downhole. Packers also may not be reliable in some applications and are often quite expensive.